Tag: electric fields

Questions Related to electric fields

Which is not an electrostatic phenomenon

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. Comb rubbed with hair attracts paper bits

  2. A blanket in winters in dark when scrambled gives electrical sparks

  3. Two people shaking hands feel a small spark in winters

  4. Heat is generated in a resistor carrying current

Show answer
Correct Option: D
Explanation:

(d) is based on Joule's Law.

Rest are electrostatic phenomenon.

.......... Property develops in comb due to friction.

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. Attractive

  2. Repulsive

  3. Both

  4. None

Show answer
Correct Option: A
Explanation:

An attractive property is develop in the comb due to friction. The comb on rubbing over dry hairs is aid to be charged.

......... Charge is produced by friction

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. Stationary

  2. No

  3. Attractive

  4. All

Show answer
Correct Option: A
Explanation:

The stationary charge (i.e static electricity) is produced by friction.

If a glass rod is rubbed on silk cloth and then brought near the bits of paper it...... then.

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. Attracts

  2. Repel

  3. Both

  4. None

Show answer
Correct Option: A
Explanation:

If a ordinary glass rod is rubbed on the silk cloth is brought near bits of paper, it is found that they have acquired the attractive property. The glass rod get charged on rubbing.

What is known as electrostatic attraction?

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. When negatively charged atom is attracted towards positively charged atom

  2. When positively charged atom is attracted towards negatively charged atom

  3. When positively charged atom is attracted towards positively charged atom

  4. When negatively charged atom is attracted towards negatively charged atom

Show answer
Correct Option: A
Explanation:

When negatively charged atom is attracted towards positively charged atom, it is known as electrostatic attraction.


Option A is correct.

What is known as electrostatic repulsion?

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. When two positively or two negatively charged electrons come closer to each other then they repel from each other

  2. When two charged electrons come closer to each other then they repel from each other

  3. When positively and negatively charged electrons come closer to each other then they repel from each other

  4. None

Show answer
Correct Option: A
Explanation:

When two positively or two negatively charged electrons come closer to each other then they repel from each other. Then it is known as electrostatic repulsion.


Option A is correct.

The law that describes the force as directly proportional to magnitude of charges and inversely proportional to the distance between the charges is known as :

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. Newton's law

  2. Coulomb's law

  3. Gauss's law

  4. Ohm's law

Show answer
Correct Option: B
Explanation:

Newton's law : force $F=ma$  where m=mass and a=acceleration

Coulomb's law : force $F=\dfrac{kq _1q _2}{r^2}$ where $q _1, q _2 $ are charges and $r=$ separation of charges and $k=$ proportionality constant.
Gauss's law : the electric flux $\phi=\dfrac{q}{\epsilon _0}$ 
Ohm's law : Potential across a wire of resistance R is $V=IR$ where I is the current. 

On which factors from below does Coulomb's law(i.e. law of electrostatic attraction and repulsion) depends?

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. Magnitude of charges

  2. Distance between charges

  3. Both magnitude and distance between charges

  4. None of the above

Show answer
Correct Option: C
Explanation:

Coulomb's Law : $\dfrac{kq _1q _2}{r^2}$
It depends on both magnitude of charges and distance between them. 

Electric charges which are under the action of electric forces are known as :

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. Electrostatic

  2. Electric flux

  3. Electric field

  4. Electric field lines

Show answer
Correct Option: A
Explanation:

Electrostatic : when the charges are under action of electric forces. 

Electric flux : It is the measure of filed lines through a given area. 
Electric field  : the electric force per unit charge. 
Electric field lines : it measure the nature of charges, field lines is outward form positive charges and inner-ward for negative charges.

What does coulomb's law of attraction and repulsion states?

physics electric fields introduction to electrostatic force electric force charging and discharging

  1. F is directly proportional to $q _1q _2$ and inversely proportional to $(r _{12})^2$

  2. F is directly proportional to $q _1q _2$ and inversely proportional to $(r _{12})$

  3. F is indirectly proportional to $q _1q _2$ and directly proportional to $(r _{12})^2$

  4. None

Show answer
Correct Option: A
Explanation:

The Coulomb law is the force between two charges $q _1$ and $q _2$ when the separation between them is $r _{12}$. 

Here , $F=\dfrac{kq _1q _2}{r _{12}^2}$
Thus, F is proportional to $q _1q _2$ and invewrsely proportional to $r _{12}^2$.